Self-dudding ordnance fuze

ABSTRACT

An ordnance fuze having a selector rotor and an arming rotor initially held in an unarmed position by a rod which can be released by the rotation of a wind vane to move clear of the arming rotor and thus free the arming rotor to rotate to an armed position. A timer revolves a plate to block the movement of the rod after a predetermined time lapse if the vane has not already released it, thus preventing the arming of the fuze. An externally operated control limits the movement of the rod to either permit or prevent rotation of the selector rotor to direct the blast of the primer to either an instantaneous detonator or a delay detonator.

llite States atent [72] Inventor George S. Briggs Adelphi, Md. [21 App]. No. 858,670 [22] Filed Sept. 17, 1969 [45] Patented Aug. 24, 1971 [73] Assignee The United States of America as represented by the Secretary of the Navy [54] SELF -DUDDING ORDNANCE FUZE 15 Claims, 3 Drawing Figs.

{52] US. Cl 102/74, 102/76,102/81.2, 102/83 [51] Int. Cl r. F42c 1/00, F42c 15/12 [50] Field of Search 102/70, 76, 81, 81.2, 74, 83, 75, 79

[56] Relerencs Cited UNITED STATES PATENTS 1,681,390 8/1928 Bold 102/86 Primary ExaminerSamuel W. Engle Attorneys-J. P. Dunlavey and .l. O. Tresansky ABSTRACT: An ordnance fuze having a selector rotor and an arming rotor initially held in an unarmed position by a rod which can be released by the rotation of a wind vane to move clear of the arming rotor and thus free the arming rotor to rotate to an armed position. A timer revolves a plate to block the movement of the rod after a predetermined time lapse if the vane has not already released it, thus preventing the arming of the fuze. An externally operated control limits the movement of the rod to either permit or prevent rotation of the selector rotor to direct the blast of the primer to either an instantaneous detonator or a delay detonator.

Patented Aug. 24, 1971 2 Sheets-Sheet 2 SELF-DUDDING ORDNANCE F UZE CROSS-REFERENCES TO RELATED APPLICATIONS This invention is an improvement on U.S. Pat. application Ser. No. 726,379, filed on May 3, 1968.

BACKGROUND OF THE INVENTION This invention generally relates to ordnance fuzes and more particularly to ordnance fuzes for use in low-level delivered ordnance devices.

In high-altitude released, flight-stabilized bombs, it has been conventional practice to include fuzes having a safety and arming device that uses a wind driven vane to arm the fuze. Typically, the vane must sense a predetermined high wind velocity before an actuating mechanism, such as a centrifugal clutch, is actuated to arm the fuze. This technique has proved feasible because the stabilized orientation of the falling bomb produces a steady, high-velocity wind stream which exerts a sustained torque on the vane shaft of a substantial magnitude necessary to operate the actuating mechanism. In the case of low-level released bombs or tumbling bombs, a steady, highvelocity wind stream on the vane does not exist, and only a short time is available in which the fuze may arm. Hence, the fuze for such a bomb must arm quickly and in the presence of a much lower velocity wind stream.

A serious problem inheres in an ordnance fuze that is armed quickly in the presence of a low-velocity wind stream in that such a fuze is inherently more easily actuated by fortuitous circumstances and negligent handling. Personnel handling ordnance tend to develop a casual attitude toward their work and often ignore the dangers that attend the careless and the curious. The presence of a vane appears for some to constitute an irresistable temptation to spin the same. While this contingency presents but slight danger in the case of a fuze which requires a high rate of sustained spinning, the same contingency presents a grave threat in the case of a fuze that requires only a low rate of spin and is armed quickly. Moreover, some ordnance storage areas contain sources of compressed air for cleaning and driving power tools, and it is conceivable that a stream of compressed air may be inadvertently directed against the vane. While thevane frequently has means for locking it against rotation priorto release from the delivery vehicle, these locking means are not fool-proof and occasionally become dislodged because of careless handling, tampering, etc. Consequently, it is imperative that ordnance fuzes of this type be made tamperproof to preclude the possibility of inadvertent premature arming and detonation.

SUMMARY OF THE INVENTION Accordingly, it is an object of this invention to provide a low-velocity armed ordnance fuze immune to premature armmg.

Another object of this invention is to provide a mechanical ordnance fuze for a low-level delivery ordnance device which is secure against inadvertent premature arming.

Another object of this invention is to provide a tamperproof ordnance fuze for a low level delivery tumbling bomb which is positively armed by a low velocity intermittent wind stream.

Yet another object of this invention is to provide a tamperproof ordnance fuze with the option of selecting either an instantaneous or a delayed detonation after fuze functioning.

Briefly, in accordance with one embodiment of this invention, these and other objects are attained by providing an ordnance fuze having a timer and a vane, both started simultaneously. The vane operates to free an arming rotor release rod after a given number of revolutions thereby rendering the fuze armed, while the timer operates to block the rod after a predetermined time lapse if the vane has not already rotated fast enough to release it,. thus causing the fuze to remain unarmed. I

A more complete appreciation of the invention and its many attendant advantages will develop as the same becomes better understood by reference to the following detailed description formed therein a forwardly opening centrally disposed cavity' 12 and a rearwardly opening centrally disposed chamber 13 with a concave ceiling 14. Cavity 12 and chamber 13 are interconnected by an axial bore 11 having an enlarged cylindrical portion 15 and a narrow portion 16, the forward half of which is internally threaded at 17. A cylindrical insert 18 having a forwardly facing concave surface 19 fits into the rearward extremity of cylindrical casing 10 thereby closing chamber 13. A tubular casing 20 closed at one end fits over cylindrical insert 18 and the rearward portion of cylindrical casing 10. The forward open end of tubular sheath 20 is threadedly secured to casing 10 and compresses an O-ring seal 21, seated within a groove around the cylindrical casing, providing hermetic sealing between tubular casing 20 and cylindrical casing 10.

An end cap or cover 22 is secured across the front of cylindrical casing 10, completely sealing cavity 12. The cover is crimped into a groove 23 formed in casing 10. Another O-ring seal 24 disposed in a groove 25 in casing 10 forward of groove 23 provides hermetic sealing between cover 22 and casing 10. The top of cover 22 is provided with a closed curvilinear score 26 and a ripping tab 27 is secured to the cover inwardly of score 26. A nib 28 projects into cavity 12 from the underside of cap 22 below ripping tab 27 for a purpose to be described hereinafter. A selector control knob 30 is rotatably secured to cover 22 and has projecting inwardly of cavity 12 an integral portion 32 from which an arm 34 extends radially for a purpose to be described hereinafter.

Projecting upwardly around enlarged portion 15 of axial bore 11 is a tubular extension 35 of casing 10. A cylindrical bushing 36 slideably fits within tubular extension 35 and within enlarged portion 15 of axial bore 11. As most clearly shown in FIG. 2, bushing 36 has machined on the exterior surface thereof a pair of diametrically opposing flats 38 terminating at shoulders 40. Fitted into a circumferential groove 43 around tubular extension 35 is a snap ring 42 having a pair of diametrically opposed lugs 44 projecting radially inwardly therefrom through a pair of complementary diametrically opposed cuts 45 through tubular extension 35. Lugs 44 abut against bushing flats 38 thereby preventing rotation of bushing 36. Lugs 44 will also engage shoulders 40 when bushing 36 is extended forwardly, as will be explained hereinafter.

A sleeve 46 having a square axial bore 47 is rotatably journaled coaxially within bushing 36. An air-driven impeller or vane 48 is rigidly secured to the top of sleeve 46 as by crimping at 49. A compression spring 50 is disposed within enlarged bore portion 15 and urges bushing 36 and sleeve 46 axially outward, but cover 22 normally restrains such outward motron.

An elongate arming pin 52 is disposed within axial bore 11 and is provided with a lower reduced diameter portion 56 and a threaded portion 54 threadedly engaged with threaded portion 17 of axial bore 11. The upper end portion 57 of arming pin 52 has transverse slot 58 formed therein in which is disposed a forwardly tapering blade 62 pivoted around a pin 60. The transverse dimension of blade 62 at its wide forward end is substantially the same as the widest transverse dimension of square bore 47 of sleeve 46, so that the torque exerted on sleeve 46 by vane 48 will be transmitted to arming pin 52 via the forward end of blade 62. I

An omnidirectional inertia detonator assembly 64 is positioned within chamber 13. Detonator assembly 64 has a cupshaped housing 66 with an axial passage 70 through the rearward end thereof in which is secured a primer 72. A slider 68 is slideably disposed within housing 66 and has secured to the rearward end thereof a firing pin 74. Interposed between slider 68 and the inside bottom of housing 66 is a compression spring 76 which normally maintains axial separation of firing pin 74 and primer 72. Slider 68 has an axial well 79 and an intersecting transverse bore 78 which contains a pair of ball detents 80. Reduced portion 56 of arming pin 52 normally extends between the ball detents 80 radially outwardly of the outside dimension of slider 68 and preventing the axial movement of slider 68 within cup 66, thereby precluding premature penetration of firing pin 74 into primer 72.

A transverse bore 82 is formed in casing to provide a passage from the outside of casing 10 to narrow portion 16 of axial bore 11, and slideably holds a locking pin 84. A longitudinal bore 86 is formed in casing 10 parallel to axial bore 11 and extends from cavity 12 to chamber 13 and intersecting bore 82. Slideably disposed within bore 86 is a rod 90 having a top portion 91, an upper enlarged portion 92 of somewhat smaller cross-sectional dimension than bore 86, and an intermediate enlarged portion 94 of approximately the same crosssectional dimension as bore 86. A compression spring 96 bears against the underside of enlarged portion 94 urging rod 90 forwardly.

Rotatably mounted in a pair of parallel transverse bores 97 and 99 formed through cylindrical insert 18 and perpendicular to the longitudinal axis of the fuze are selector rotor 98 and arming rotor 100, respectively, both of a cylindrical configuration. Coiled about a stud 102 projecting from one end 104 of selector rotor 98 is a torsion spring 1 10 which biases rotor 98 for rotation about its longitudinal axis, and coiled about a stud 106 projecting from one end 108 of arming rotor 100 is a torsion spring 112 for biasing rotor 100 for rotation about its longitudinal axis. A pair of radial slots 114 and 116 are formed in the other end of rotors 98 and 100, respectively. A pair of transverse bores 118 and 119 are formed through arming rotor 100, respectively, containing a delay detonator 120 and an instantaneous detonator 121. An axial aperture 117 is formed centrally in cylindrical insert 18 and a transfer detonator 122 is disposed therein. Thus, it is seen that primer 72 communicates via axial passage 70, transfer detonator 122 and axial aperture 117 with selector rotor 98, and more particularly, with a circumferential are around the surface of rotor 98 that is presented to axial aperture 117 as rotor 98 rotates. A transverse channel, or bore, 123 is formed through selector rotor 98 to provide communication between axial aperture 117, via an aperture 125 connecting bores 97 and 99, and, when rotor 100 has been rotated 90, to delay detonator 120 in bore 118. A second transverse channel, or bore, 124 spaced from transverse bore 123, opens on the aforesaid circumferential are around rotor 98 so that when rotor 98 is rotated 90", one end of bore 124 will be aligned with axial aperture 117, and the other end of bore 124 will be aligned with another aperture 127 connecting bores 97 and 99. Thus, a 90 rotation of rotor 98 will establish a communication between primer 72 and, when rotor 100 has been rotated, instantaneous detonator 121 via axial passage 70, transfer detonator 122, transverse bore 124 and aperture 127. In the position shown in FIG. 1, rotor release rod 90 extends downwardly through cylindrical insert 18 into both slots 114 and 116 preventing rotation of the selector rotor 98 and arming rotor 100.

Looking now at H6. 3, a timer having a coil torsion spring 126 and a conventional escapement mechanism 128 connected thereto by a gear train 129 is disposed within cavity 12. A circular timer plate 130 having gear teeth 131 around an arc of its outside periphery engaged with gear train 129 is driven by torsion spring 126 at a speed governed by escapement mechanism 128. Timer plate 130 is disposed for rotation in a horizontal plane above rotor release rod 90, and has a generally keyhole-shaped aperture 132 with a wide portion 134 and a narrow portion 136 which are alignable with rod 90 by rotation of plate 130. The periphery of timer plate 130 has formed therein a notch 138 into which a tang 140 of a locking lever 142 fits to prevent rotation of the timer plate 130. Locking lever 142 has a pair of spaced parallel horizontal arms 144 and 146 separated by a perpendicular cross member 148. Locking lever 142 is pivoted about pivot pin 150, fixed in casing 10, and is urged for clockwise rotation by a coiled torsion spring 152.

In operation, when a bomb containing the subject fuze is released from the delivery aircraft, a lanyard connected between ripping tab 27 and the bomb rack of the delivery aircraft rips the center portion out of cover 22 along score 26. As the cover is ripped from the fuze casing, the nib 28 will release the upper arm 144 of the locking lever 142, and torsion spring 152 will rotate locking lever 142 clockwise thus removing locking tang 140 from notch 138 thereby allowing torsion spring 126 to begin rotating timing plate 130 at a speed governed by escapement mechanism 128 connected through gear train 129 to timing plate 130. Simultaneously, compression spring 50 pushes bushing 36 axially forward in enlarged bore portion 15 taking with it sleeve 46 and wind vane 48 secured thereon. The vane is rotated by the air stream whereupon arming pin 52 will be unscrewed from threaded portion 17 of bore 11 through the coaction of tapering blade 62 in square bore 47 of sleeve 46. As pin 52 withdraws, ball detents are released to move radially inward and the inertia detonator assembly 64 will be enabled. However, compression spring 76 continues to maintain the separation between firing pin 74 and primer 72. As vane 48 continues to rotate, arming pin 52 will advance forwardly until reduced portion 56 thereof is aligned with transverse bore 82 and locking pin 84 therein. At this time, locking pin 84 is free to slide radially inward in bore 82. When spring 126 has rotated timer plate 130 so that wide portion 134 of keyhole aperture 132 is aligned with bore 86, rod moves upwardly through wide portion 134 of keyhole aperture 132, pin 84 being pushed inwardly by enlarged diameter portion 94, and the lower end of rotor release rod 90 clears arming rotor 100, thus permitting its torsion spring 112 to rotate it 90 thereby aligning bore 118 and delay detonator therein with primer 72 and thus arming the fuze.

If, prior to launching, arm 34 has been rotated by knob 30 so that it extends directly over bore 86 then when rod 90 escapes through keyhole aperture 132, it will be stopped by the arm 34 and prevented from clearing slot 114 of selector rotor 98. Thus, the blast from primer 72 and transfer detonator 122 will be directed through bore 123 to delay detonator 120 in bore 118. If, in turn, the arm 34 has been rotated so that it is clear of bore 86 and thus permits the rotor release rod 90 to move forward the full extent, then the lower end thereof will clear selector rotor 98 and permit a 90 rotation thereof so that bore 124 is aligned between axial aperture 117 and aperture 127, thereby providing communication between primer 72, transfer detonator 122 and the instantaneous detonator 121 in bore 119.

In case, however, the bomb his been tapered with and cover 22 has been opened, however slightly, the nib 28 will be lifted clear of lever arm 144 to permit rotation of locking lever 142 by spring 152 so that timer plate is released for rotation. Plate 130 will rotate until aperture 132 is presented to reduced end 91 of rod 90 whereupon rod 90 will move forward into aperture 132 to the extent permitted by the engagement of pin 84 with wide diameter portion 94. Plate 130 will continue to rotate until the trailing edge of narrow portion 136 of aperture 132 engages the protruding end of rod 90, whereupon the rotation of plate 130 will be halted. Then when vane 48 is rotated sufficiently for rod 90 to be released by locking pin 84, rod 90 will move up another increment, limited by the reduced dimension of the narrow portion 136 of the keyhole aperture 132 blocking the passage of the upper enlarged diameter portion 92 of rod 90 through plate 130. Subsequent release of rod 90 by clockwise motion of the timer plate 130 is positively prevented by the action of torsion spring 126, and further counterclockwise rotation of timer plate 130 is prevented by the extension of top portion 91 of rotor release rod 90 through the narrow portion 136 of keyhole aperture 132. Thus, rod 90 is permanently blocked, causing the fuze to be positively inactivated and safe from subsequent fortuitous arming.

The timed run of timer plate 130 may be selected in the range of one second, for example, so that is is physically impossible for a man to remove the cover and spin the vane far enough to release rod 90 before the timed run of timer plate 130. The fuze is therefore made to be virtually tamperproof.

Obviously, numerous variations and modifications of the above-described best mode or preferred embodiment of the invention may be made.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. An ordnance fuze, comprising:

a fluid rotatable vane;

a timer;

means for simultaneously unlocking said timer for the timed running thereof and said vane for fluid driven rotation thereof;

means shiftable between a first position in which said fuze is unarmed and a second position in which said fuze is armed;

means responsive to the rotation of said vane for releasing said shiftable means for movement thereof from said first to said second position; means controlled by said timer for blocking said releasing means from releasing said shiftable means after the lapse of a predetermined time period.

2. The ordnance fuze defined in claim 1 wherein said releasing means comprises;

an arming pin threadedly engaged in said fuze and operatively connected to said vane for rotation thereby;

a movable release rod engaging said shiftable arming means and holding it in said first position;

biasing means for urging said rod out of engagement with said shiftable arming means;

means controlled by the position of said arming pin for locking said rod in engagement with said shiftable arming means against the action of said biasing means, and upon a predetermined rotation of said arming pin by said vane for unlocking said rod for movement under the action of said biasing means from engagement with said shiftable arming means.

3. The ordnance fuze defined in claim 2 wherein:

said arming pin has a wide diameter portion and a narrow diameter portion;

said release rod has a wide diameter portion and a narrow diameter portion;

said locking means comprises a slidable pin extending between said release rod and said arming pin and is longer than the distance between said wide diameter portions of said arming pin and said release rod.

4. The ordnance fuze defined in claim 2 wherein said blocking means comprises: 7

a plate movable by said timer and having defined therein an aperture which is alignable with said release rod by movement of said plate to permit the passage of said rod through said plate under the action of said biasing means.

5. The ordnance fuze of claim 4 wherein:

said aperture in said plate has a wide diameter portion and a contiguous narrow diameter portion;

said release rod includes a narrow diameter portion positioned adjacent said plate, and a wide diameter portion spaced from said plate; said wide diameter portion of said aperture being slightly larger than said wide diameter portion of said rod to permit passage of said rod through said aperture;

said narrow diameter portion of said aperture being slightly larger than said narrow diameter portion of said rod, but narrower than said wide diameter portion of said rod to block passage of said wide diameter portion of said rod when said narrow diameter portion of said aperture is aligned with said rod.

6. The ordnance fuze defined in claim 1, further comprising:

a firing pin;

a primer initiatable by said firing pin;

an instantaneous detonator and a delay detonator;

means for selectively directing the path of fire initiated by said primer toward one of said instantaneous detonator and said delay detonator,

said selectively directing means being controlled by said releasing means.

7. The ordnance fuze defined in claim 6 wherein said selectively directing mean comprises:

a member movably mounted in said fuze between said primer and said instantaneous and delay detonators;

means defining a channel through said member communicating between said primer and one of said detonators;

means for biasing said member toward a predetermined orientation.

8. The ordnance fuze defined in claim 6, wherein said selectively directing means comprises:

a cylinder journaled for rotation in said fuze adjacent said primer;

a torsion spring coiled around one end of said cylinder and biasing said cylinder toward a predetermined orientation;

said cylinder having formed in one end thereof a radial slot and having formed through the central portion thereof a pair of transverse oblique channels, both extending in obliquely opposite directions from a circumferential arc around said cylinder that communicates with said primer, one of said channels extending from said primer to one of said detonators and the other channel alignable by the rotation of said cylinder between said primer and the other of said detonators,

said cylinder being releasably held from rotation by said releasing means extending into said slot.

9. The ordnance fuze defined in claim 1, further comprising:

an inertia actuated detonator;

and wherein said releasing means releasably secures said detonator in a safe position; and

said releasing means, responsive to the rotation of said vane, releases said detonator to an armed position in which a sudden deceleration will actuate said inertia actuated detonator.

10. The ordnance fuze defined in claim 9 wherein said inertia aperatural detonator comprises:

a cup having sidewalls and an apertured bottom connected at one end thereof;

a slider slidably received within said sidewalls of said cup and having a firing pin secured to the bottom thereof, a transverse bore formed through the upper end thereof, and an axial well extending from the upper end thereof to said transverse bore,

a primer secured in said cup bottom aperture;

said releasing means extending into said axial well and through said transverse bore,

. a pair of ball detents in said transverse bore releasably held apart by said releasing means to protrude beyond the outside dimension of said slider and coact with said cup sidewalls to prevent the sliding of said slides into said cup and thus releasably maintain the separation between said firing pin and said primer.

11. The ordnance fuze defined in claim 1, further comprising:

a firing pin;

a primer initiatable by said firing pin;

an inertia mass connected to one of said firing pin and said primer and responsive to a sudden deceleration to effect the forceful contact between said firing pin and said primer;

means to releasably maintain a separation between said firing pin and said primer;

an instantaneous detonator;

a delay detonator;

means movable between two position for selectively directing the path of fire initiated by said primer toward one of said instantaneous detonator and said delay detonator;

said releasing means being operatively connected to said selectively directing means for controlling the position thereof;

said releasing means also being operatively connected to said releasable maintaining means for controlling the release thereof.

12. The ordnance fuze defined in claim 11 wherein said releasing means comprises:

an arming pin threadedly engaged in said fuze and operatively connected to said vane for rotation thereby;

a movable release rod engaging said shiftable arming means and holding it in said first position;

biasing means for urging said rod out of engagement with said shiftable arming means;

means controlled by the position of said arming pin for locking said rod in engagement with said shiftable arming means against the action of said biasing means, and upon a predetermined rotation of said arming pin by said vane for unlocking said rod for movement under the action of said biasing means from engagement with said shiftable arming means.

13. The ordnance fuze defined in claim 12 wherein said blocking means comprises:

a plate movable by said timer and having defined therein an aperture which is alignable with said release rod by movement of said plate to permit the passage of said rod through said plate under the action ofsaid biasing means.

14. The ordnance fuze defined in claim 13 wherein:

said aperture in said plate has a wide diameter portion and a contiguous narrow diameter portion;

said release rod includes a narrow diameter portion positioned adjacent said plate, and a wide diameter portion spaced from said plate;

said wide diameter portion of said aperture being slightly larger than said wide diameter portion of said rod to permit passage of said rod through said aperture;

said narrow diameter portion of said aperture being slightly larger than said narrow diameter portion of said rod, but narrower than said wide diameter portion of said rod to block passage of said wide diameter portion of said rod when said narrow diameter portion of said aperture is aligned with said rod.

15. The ordnance fuze defined in claim 11 wherein said selectively directing means comprises:

a cylinder journaled for rotation is said fuze adjacent said primer;

a torsion spring coiled around one end of said cylinder and biasing said cylinder toward a predetermined orientation;

said cylinder having formed in one end thereof a radial slot and having formed through the central portion thereof a pair of transverse oblique channels, both extending in obliquely opposite directions from a circumferential arc around said cylinder that communicates with said primer, one of said channels extending from said primer to one of said detonators and the other channel alignable by the rotation of said cylinder between said primer and the other of said detonators,

said cylinder being releasably held from rotation by said releasing means extending into said slot. 

1. An ordnance fuze, comprising: a fluid rotatable vane; a timer; means for simultaneously unlocking said timer for the timed running thereof and said vane for fluid driven rotation thereof; means shiftable between a first position in which said fuze is unarmed and a second position in which said fuze is armed; means responsive to the rotation of said vane for releasing said shiftable means for movement thereof from said first to said second position; means controlled by said timer for blocking said releasing means from releasing said shiftable means after the lapse of a predetermined time period.
 2. The ordnance fuze defined in claim 1 wherein said releasing means comprises; an arming pin threadedly engaged in said fuze and operatively connected to said vane for rotation thereby; a movable release rod engaging said shiftable arming means and holding it in said first position; biasing means for urging said rod out of engagement with said shiftable arming means; means controlled by the position of said arming pin for locking said rod in engagement with said shiftable arming means against the action of saiD biasing means, and upon a predetermined rotation of said arming pin by said vane for unlocking said rod for movement under the action of said biasing means from engagement with said shiftable arming means.
 3. The ordnance fuze defined in claim 2 wherein: said arming pin has a wide diameter portion and a narrow diameter portion; said release rod has a wide diameter portion and a narrow diameter portion; said locking means comprises a slidable pin extending between said release rod and said arming pin and is longer than the distance between said wide diameter portions of said arming pin and said release rod.
 4. The ordnance fuze defined in claim 2 wherein said blocking means comprises: a plate movable by said timer and having defined therein an aperture which is alignable with said release rod by movement of said plate to permit the passage of said rod through said plate under the action of said biasing means.
 5. The ordnance fuze of claim 4 wherein: said aperture in said plate has a wide diameter portion and a contiguous narrow diameter portion; said release rod includes a narrow diameter portion positioned adjacent said plate, and a wide diameter portion spaced from said plate; said wide diameter portion of said aperture being slightly larger than said wide diameter portion of said rod to permit passage of said rod through said aperture; said narrow diameter portion of said aperture being slightly larger than said narrow diameter portion of said rod, but narrower than said wide diameter portion of said rod to block passage of said wide diameter portion of said rod when said narrow diameter portion of said aperture is aligned with said rod.
 6. The ordnance fuze defined in claim 1, further comprising: a firing pin; a primer initiatable by said firing pin; an instantaneous detonator and a delay detonator; means for selectively directing the path of fire initiated by said primer toward one of said instantaneous detonator and said delay detonator, said selectively directing means being controlled by said releasing means.
 7. The ordnance fuze defined in claim 6 wherein said selectively directing mean comprises: a member movably mounted in said fuze between said primer and said instantaneous and delay detonators; means defining a channel through said member communicating between said primer and one of said detonators; means for biasing said member toward a predetermined orientation.
 8. The ordnance fuze defined in claim 6, wherein said selectively directing means comprises: a cylinder journaled for rotation in said fuze adjacent said primer; a torsion spring coiled around one end of said cylinder and biasing said cylinder toward a predetermined orientation; said cylinder having formed in one end thereof a radial slot and having formed through the central portion thereof a pair of transverse oblique channels, both extending in obliquely opposite directions from a circumferential arc around said cylinder that communicates with said primer, one of said channels extending from said primer to one of said detonators and the other channel alignable by the rotation of said cylinder between said primer and the other of said detonators, said cylinder being releasably held from rotation by said releasing means extending into said slot.
 9. The ordnance fuze defined in claim 1, further comprising: an inertia actuated detonator; and wherein said releasing means releasably secures said detonator in a safe position; and said releasing means, responsive to the rotation of said vane, releases said detonator to an armed position in which a sudden deceleration will actuate said inertia actuated detonator.
 10. The ordnance fuze defined in claim 9 wherein said inertia aperatural detonator comprises: a cup having sidewalls and an apertured bottom connected at one end thereof; a slider slidably received within said sidewalls of said cup and having a firing Pin secured to the bottom thereof, a transverse bore formed through the upper end thereof, and an axial well extending from the upper end thereof to said transverse bore, a primer secured in said cup bottom aperture; said releasing means extending into said axial well and through said transverse bore, a pair of ball detents in said transverse bore releasably held apart by said releasing means to protrude beyond the outside dimension of said slider and coact with said cup sidewalls to prevent the sliding of said slides into said cup and thus releasably maintain the separation between said firing pin and said primer.
 11. The ordnance fuze defined in claim 1, further comprising: a firing pin; a primer initiatable by said firing pin; an inertia mass connected to one of said firing pin and said primer and responsive to a sudden deceleration to effect the forceful contact between said firing pin and said primer; means to releasably maintain a separation between said firing pin and said primer; an instantaneous detonator; a delay detonator; means movable between two position for selectively directing the path of fire initiated by said primer toward one of said instantaneous detonator and said delay detonator; said releasing means being operatively connected to said selectively directing means for controlling the position thereof; said releasing means also being operatively connected to said releasable maintaining means for controlling the release thereof.
 12. The ordnance fuze defined in claim 11 wherein said releasing means comprises: an arming pin threadedly engaged in said fuze and operatively connected to said vane for rotation thereby; a movable release rod engaging said shiftable arming means and holding it in said first position; biasing means for urging said rod out of engagement with said shiftable arming means; means controlled by the position of said arming pin for locking said rod in engagement with said shiftable arming means against the action of said biasing means, and upon a predetermined rotation of said arming pin by said vane for unlocking said rod for movement under the action of said biasing means from engagement with said shiftable arming means.
 13. The ordnance fuze defined in claim 12 wherein said blocking means comprises: a plate movable by said timer and having defined therein an aperture which is alignable with said release rod by movement of said plate to permit the passage of said rod through said plate under the action of said biasing means.
 14. The ordnance fuze defined in claim 13 wherein: said aperture in said plate has a wide diameter portion and a contiguous narrow diameter portion; said release rod includes a narrow diameter portion positioned adjacent said plate, and a wide diameter portion spaced from said plate; said wide diameter portion of said aperture being slightly larger than said wide diameter portion of said rod to permit passage of said rod through said aperture; said narrow diameter portion of said aperture being slightly larger than said narrow diameter portion of said rod, but narrower than said wide diameter portion of said rod to block passage of said wide diameter portion of said rod when said narrow diameter portion of said aperture is aligned with said rod.
 15. The ordnance fuze defined in claim 11 wherein said selectively directing means comprises: a cylinder journaled for rotation is said fuze adjacent said primer; a torsion spring coiled around one end of said cylinder and biasing said cylinder toward a predetermined orientation; said cylinder having formed in one end thereof a radial slot and having formed through the central portion thereof a pair of transverse oblique channels, both extending in obliquely opposite directions from a circumferential arc around said cylinder that communicates with said primer, one of said channels extending from said primer to one of said detonators and the Other channel alignable by the rotation of said cylinder between said primer and the other of said detonators, said cylinder being releasably held from rotation by said releasing means extending into said slot. 